Haloethylene polymers stabilized with diesters of aliphatic dicarboxylic acids and hydroxy benzophenones



United States Patent it HA'LOETHYLENE POLYMERS STABILIZED WITH DIESTERS OF ALlPHATIC DICARBOXYLIC ACIDS AND HYDROXY BENZOPHENONES "Carl B. Havens and Gerald A. Clark, Midland, Mich., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. Original application Aug, 2,.v 1956, Ser. No. 601,644, new Patent No, 2,894,022, dated July 7, 1959. Divided and this application May 6, 1959, Ser. No. 811,273

'6. Claims. (Cl. 260-45.85)

This invention relates to new organic compounds and to polymeric compositions containing the same. More particularly it relates to new organic compounds finding utility as. light stabilizers for haloethylene polymers.

This application is a division of U. S. Serial No. 601,- 644, filed August 2, 1956,,now US. Patent No. 2,894,- 022.

Haloethylene polymers such as those containing at least '50 percent vinylidene chloride, are known to be highly sensitive to theiefrects of elevated temperatures and of light and under prolonged exposure to heat and light may become so degraded and discolored as to be commercially useless. It has been common practice to blend certain compounds with the polymer to stabilize it against the degradative eifects of heat and light. Several of such compounds, however, are highly colored materials which impart an objectionable initial color to the stabilized composition which prevents the production of a commercially saleable white composition. Still other disadvantages of many of the previous compounds are a high odor level and volatility. Any odor in the stabilizer will be transferred to the stabilized composition. When volatile stabilizers are employed the stabilizers volatilize out of the composition leaving the composition in time unprotected against the degradative effects of light, particularly ultraviolet light. In addition all of the compounds vary in their ability to absorb ultra-violet light and it is impossible to predict the elfectiveness of any particular compound with any degree of certainty, and even then some of the initially useful compounds wherein the compositions lose some of their effectiveness for absorbing ultraviolet light over a prolonged period of time.

In view of the above problems it would be desirable and it is the principal object of this invention to provide a new group of organic compounds having the stated utility.

It is a fmther object to provide a group of such compounds which have little or no color and have a low odor level.

Another object is to provide a group of such compounds which have low volatility.

The above and related objects are accomplished by means of a group of diesters having the general formula:

5 f f t 0 o 0 o {Brag l aawsnao@t{ 5 X X X X wherein n is a whole number from 2 to 8, X may be hydrogen, halogen, or alkyl, and one Y in each benzophenone group is hydrogen and the other Y in each such group is hydroxyl. The objects are further realized with compositions comprising such diesters together with haloethylene polymers.

The diesters of this invention are easily prepared by ICC 2. known esterification reactions. In an illustrative preparation, 0.5 mole of adipyl chloride was added dropwise to 2 moles of 2,4-dihdroxybenzophenone in 1250 milliliters of toluene and 125 milliliters of pyridine. The reactants were stirred for 12 hours at 70 to C. The reaction mixture was cooled, Washed .sqi ntially with water, 4 percent aqueous sodium hydroxide, dilute H01 and finally twice with water. The solvent was removed by distillation after which the product was recrystallized from alcohol. The dried bis(3-hydroxy-4-benzoyl phenyl) adipate was in the form of pale yellow crystals melting at 125 to 126 C. Other diesters may be prepared in a similar manner by employing as reactants the appro priate dihydroxy benzophenone and-acyl chloride. As

typical of other representative diesters may be mentioned The diesters of this invention are effective stabilizers for haloethylene polymers, particularly those polymers containing at least 50 percent vinylidene chloride. Such polymers are known to be especially sensitive to the effects of light. The compounds are eifective when employed in amounts of from 1 to 10 percent, preferably 1 to 3 percent of the weight of the polymer used irrthe composition. Cornpositions containing less than 1 percent exhibit littleniore stability than unstabilized'compositions. No beneficial result accrues from the use of more than 10 percent, and the cost and physical properties, such as strength, of the compositions suffer.

The diesters may be used in polymer compositions containing the common additives such as pigments, fillers, heat stabilizers, and plasticizers. They likewise may be used in combination with other known light stabilizers.

The advantages of the compositions of this invention will be more apparent from the following illustrative examples wherein all parts and percentages are by weight.

EXAMPLE 1 Two sample compositions were prepared from polyvinylidene chloride. One composition was left unstabilized for comparative purposes and to the other composition was added 5 percent of bis(p-salicyloylphenyl) adipate. The compositions were compression molded to a thickness of 0.015 inch. The moldings were exposed to direct sunlight at 43 N. latitude in the State of Michigan for 33 days. The degree of degradation due to exposure was determined by a comparison of light transmission through the moldings before and after exposure and is reported as percent loss in transmission in the following Table I.

The stabilized composition undergoes only about onethird as great a color change as the corresponding but unstabilized composition.

EXAMPLE 2 Sample compositions were prepared from 89.5 parts it of a copolymer prepared from percent vinylidene chloride and 15 percent vinyl chloride, 0.5 part sodium tripolyphosphate as a heat stabilizer, 7 parts of a fatty acid ester of pentaerythritol sold commercially as J-lS by Table II Color after exposure Stabilizer Similar results are obtained in stabilizing polyvinyl chloride with any of the new diesters.

We claim:

1. A light stable thermoplastic composition comprising a thermoplastic haloethylene polymer and from 1 to 10 percent of the weight of said polymer of a diester having the following general formula:

Y Y Y 1 if i i X C O-G-(OHah-C-O X 4 wherein n is a positive whole number of from 2 to 8. X is selected from the group consisting of hydrogen, halogen, and alkyl, and one Y in each benzoplienone group is hydrogen and the other Y in each such group is hydroxyl.

2. The composition claimed in claim 1, wherein said diester has the formula:

3. The composition claimed in claim 1, wherein said diester has the formula:

OH OH O ll alamttogl 4. The composition claimed in claim L Whereinsaid haloethylene polymer is a copolymer composed of at least 50 percent by weight of vinylidene chloride.

5. The composition claimed in claim 1, wherein said haloethylene polymer is a copolymer of vinylidene chloride and vinyl chloride.

6. The composition claimed in claim 1, wherein said haloethylene polymer is polyvinylchloride.

No references cited. 

1. A LIGHT STABLE THERMOPLASTIC COMPOSITION COMPRISING A THERMOPLASTIC HALOETHYLENE POLMER AND FROM 1 TO 10 PERCENT OF THE WEIGHT OF SAID POLYMER OF A DIESTER HAVING THE FOLLOWING GENERAL FORMULA: 